Menstrually occurring toxic shock syndrome (TSS), a severe and sometimes fatal multi-system disease associated with infection or colonization by Staphylococcus aureus (S. aureus) bacteria, has been linked to the use of tampons during menstruation. The disease is believed to be caused by toxic shock syndrome toxin-1 (TSST-1), the toxin produced by the majority of Staphlococcal strains isolated from menstrual TSS patients.
Subsequent to the publication of reports associating toxic shock syndrome with the use of tampons, a number of investigators undertook studies designed to evaluate the effect of tampons on growth of S. aureus bacteria as well as the effect of tampons on the production of TSST-1 by that bacteria. Early efforts to elucidate the role of tampons in TSS yielded conflicting data. Schlievert et al. (Obstet. Gynecol., Vol. 64, pp. 666-670, November 1984) studied the effect of tampons on S. aureus to evaluate whether or not tampon components increase growth of S. aureus and production of toxic shock syndrome toxin-1. It was concluded that, under the test conditions of their study, tampon components provide neither nutrients for growth of toxic shock syndrome S. aureus nor factors that induce production of toxic shock syndrome toxin-1 above control levels. After six hour incubation, some commercially available tampons which were tested were inhibitory to bacterial growth and suppressed toxin production. Others suppressed toxin production but did not inhibit cell growth. One tampon inhibited cell growth but increased the amount of toxin produced. On the other hand, Tierno and Hanna (Contraception, Vol. 31, pp 185-194, 1985) reported that in their experiments tampons did stimulate S. aureus to produce TSST-1.
Reiser et al. (J. Clin. Microbiol., Vol. 25, No. 8, pp 1450-1452, August 1987) thereafter reported the results of tests they conducted to determine the effect of four brands of tampons on production of toxic shock syndrome toxin-1. The amount of air available to the tampons which were tested was limited to that contained in sacs (made from cellulose sausage casing with a molecular weight cut-off of less than 10,000) in which the tampons were enclosed during testing. This method was deemed advantageous in that the limited amount of available air was thought to mimic more closely than previously used methods the in vivo condition in the vagina during menstruation with a tampon in place and in that the tampons which were tested were not altered prior to testing. The results of the tests conducted by Reiser et al. indicated that tampons provide increased surface area for the S. aureus bacteria to grow and adequate oxygen for toxin production. No significant inhibition of growth of the staphylococci bacteria or TSST-1 production by any of the tampons tested was noted.
Robbins et al., publishing in J. Clinical Microbiol., Vol. 25, No. 8, pp. 1446-1449, August 1987 at the same time as Reiser et al., reported the effect of 17 commercially available tampons on TSST-1 toxin production using a disk-membrane-agar (DMA) method, with incubation at 37.degree. C. for 19 hours under 5% CO.sub.2 in air. Filter membranes overlaying agar medium (with or without blood) in small petri dishes were spread inoculated with a TSST-1 producing strain of S. aureus. Robbins et al. concluded that the main role of tampons in TSS may be that of providing a fibrous surface for heavy colonization and sufficient air for TSST-1 production. In addition, they found evidence of inhibition of TSST-1 production by additives such as the deodorant/surfactant used in a commercially available deodorant tampon and a decrease in TSST-1 production by inhibiting growth of S. aureus as was observed in the case of a different commercially available tampon. It was thought that both inhibition of TSST-1 production and inhibition of S. aureus growth might prove to be important in reducing the risk of TSS.
U.S. Pat. No. 4,405,323 to Auerbach discloses a tampon designed to eliminate the hazards of toxic shock syndrome and dysmenorrhea. The tampon has incorporated therein an antibacterial agent which is said to disperse on contact with body fluids and prevent development of the organisms which produce the toxins which cause toxic shock syndrome. Among the antibacterial materials disclosed for use are povidone-iodine compound, mercury, zinc, penicillin, erythromycin and nitrofurazone.
Patent Cooperation Treaty Publication No. WO 86/05388 (published Sep. 25, 1986) to Kass teaches that the inclusion of a salt of a nontoxic divalent cation in absorptive pads, e.g. catamenial tampons, inhibits production of toxic shock syndrome toxin-1 and other staphylococcal products during use of said absorptive pad. Suitable salts include those of magnesium, barium, calcium or strontium (preferred) or of other divalent cations such as zinc, manganese, copper, iron, nickel and the like. The anionic portion of the salt is not critical. Magnesium stearate and magnesium acetate are particularly preferred salts for use in the invention.
In U.S. Pat. No. 4,374,522 to Olevsky it is stated that patterns of use of catamenial tampon seem to indicate that high absorptive capacity with the concomitant extended period of use of certain tampons are factors which contribute to the formation of toxic shock syndrome. The invention theorizes that tampons having limited absorptive capacity and requiring relatively more frequent changes may be desirable. The Olevsky patent provides a tampon made of conventional cellulosic materials, such as rayon fibers, which have been compressed into a bullet-shape with an open bottom surface sealed by a fluid impermeable sheet. The fluid impermeable bottom and the traditional bullet shaped pledger define a hollow core central reservoir area which is said to serve as a reservoir for excess menstrual fluid.
U.S. Pat. No. 4,431,427 to Lefren et al. discloses menstrual tampons comprising physiologically safe, water-soluble acids in their monomeric, oligomeric or polymeric forms. Citric, glycolic, malic, tartaric and lactic acids are disclosed as being useful in the practice of the invention. The presence of one or more of the above-noted acids in a tampon is said to inhibit the growth of bacteria responsible for toxic shock. Where an acid is used in its polymeric form, the tampon may additionally include an enzyme to hydrolyze the polymeric acid to its monomeric form.
Canadian Patent No. 1,123,155 to Sipos discloses a catamenial tampon for preventing toxic shock syndrome during menstrual flow. The body of the tampon, which is open at the insertion end and is closed at the withdrawal end, is snugly surrounded in its expanded condition by a fluid proof, thin and flexible membrane. This membrane, which can be made of polyethylene sheet, is biased against the vaginal wall during use of the tampon, is neutral to the vaginal mucosa and is completely impermeable to bacteria, viruses and toxic decomposition products of the menstrual flow.
Canadian Patent No. 1,192,701 to Bardhan discloses a tampon for the absorption of menstrual flow and comprising an inner layer of liquid-absorbent material and an outer layer which surrounds and encloses the inner layer. Menstrual discharge may flow inwardly to the inner layer but the outer layer is impervious to the passage of menstrual fluid outwardly from the inner layer. A plurality of liquid absorbent wicks extending from the inner layer through apertures formed in the outer layer serve as conduits for the flow of menstrual discharge from outside the tampon to the inner layer thereof. The disclosed structure is said to minimize the availability of discharge outside the tampon with a resulting reduction in the likelihood of growth of S. aureus and consequently its production of toxin. This patent also discloses that an antimicrobial compound which is bactericidal or bacteriostatic to S. aureus may be included in the inner layer. The antimicrobial agent may take the form of an antibiotic (such as penicillin, erythromycin, tetracycline or neomycin), a chemotherapeutic agent (such as a sulfonamide) or a disinfectant (such as phenol). The patent states that since the tampon is protected by its outer layer from contact with the vaginal wall, the risk of an allergic or other adverse reaction to the anti-microbial agent is minimized, and since the antimicrobial agent is also protected by the outer layer from contact with menstrual discharge, there is little risk of the destruction of commensal organisms in the vagina or development of resistance to the antimicrobial agent by S. aureus in any menstrual discharge outside the vagina.
S. Notermans et al. (Journal of Food Safety, Vol. 3 (1981), pages 83-88) reported that glyceryl monolaurate, when used in the proportion of 5 g per kg. of meat slurry (pH 6.0-6.2) inhibited toxin. productions by Clostridium botulinum type A, type B and type E. This article does not mention Staphylococcus aureus nor any toxin(s) produced therefrom nor does it mention absorbent products or toxic shock syndrome.
U.S. Pat. No. 4,585,792 to Jacob et al. discloses that L-ascorbic acid when topically applied to the vaginal area of a human female during manses will inactivate toxins known to contribute to Toxic Shock Syndrome. The ascorbic acid compound may be carried by a vaginal tampon. The disclosure of U.S. Pat. No. 4,722,937, is to the same effect.
U.S. Pat. No. 4,413,986 to Jacobs discloses a sterilely-packaged tampon assembly for sterile insertion of a tampon into the vagina and having a guide tube telescoped around an insertion tube and a flexible sheath attached to the inner end of the guide tube and tucked into the inner end of the insertion tube. In use, as the insertion tube is pushed through the guide tube and into the vagina, the flexible sheath is pulled over the inner end of the insertion tube and extends along the exterior thereof. The portion of the insertion tube which is inserted into the vagina is at all times fully sheathed by the flexible sheath.